Streams dry and ecological uniqueness rise: environmental selection drives aquatic insect patterns in a stream network prone to intermittence

Hydrobiologia - The study of variation of species composition among sites is key to understanding community ecology, but few studies have assessed beta diversity patterns in highly dynamic stream...     

Biotechnological synthesis of Pd/Ag and Pd/Au nanoparticles for enhanced Suzuki–Miyaura cross-coupling activity

Bimetallic nanoparticle catalysts have attracted considerable attention due to their unique chemical and physical properties. The ability of metal-reducing bacteria to produce highly catalytically active monometallic nanoparticles is well known; however, the properties and catalytic activity of bimetallic nanoparticles synthesized with these organisms is not well understood. Here, we report the one-pot biosynthesis of Pd/Ag (bio-Pd/Ag) and Pd/Au (bio-Pd/Au) nanoparticles using the metal-reducing bacterium, Shewanella oneidensis, under mild conditions. Energy dispersive X-ray analyses performed using scanning transmission electron microscopy (STEM) revealed the presence of both metals (Pd/Ag or Pd/Au) in the biosynthesized nanoparticles. X-ray absorption near-edge spectroscopy (XANES) suggested a significant contribution from Pd(0) and Pd(II) in both bio-Pd/Ag and bio-Pd/Au, with Ag and Au existing predominately as their metallic forms. Extended X-ray absorption fine-structure spectroscopy (EXAFS) supported the presence of multiple Pd species in bio-Pd/Ag and bio-Pd/Au, as inferred from Pd–Pd, Pd–O and Pd–S shells. Both bio-Pd/Ag and bio-Pd/Au demonstrated greatly enhanced catalytic activity towards Suzuki–Miyaura cross-coupling compared to a monometallic Pd catalyst, with bio-Pd/Ag significantly outperforming the others. The catalysts were very versatile, tolerating a wide range of substituents. This work demonstrates a green synthesis method for novel bimetallic nanoparticles that display significantly enhanced catalytic activity compared to their monometallic counterparts.     

Genomic characterization of invasive meningococcal X isolates from Brazil, 1992–2022

International Microbiology - Invasive meningococcal disease (IMD) is a major health problem. Given the post-COVID-19 pandemic scenario with the loosening of the non-pharmacological measures to...     

Dihydrophenanthrene Dimers: Why and Where It Is Possible to Isolate Their Precursors

An interesting class of compounds of natural origin is dihydrophenanthrene dimers, which are characterized by a series of remarkable biological properties. Considering the hypothesis that each dimer is obtained through a biosynthetic mechanism that involves the coupling of the corresponding radicals of the single dihydrophenanthrene unit, we identified 29 dihydrophenanthrenes. Of these dihydrophenanthrenes, 11 were new compounds that could be isolated from 10 different plant species; 11 had already been identified, but not yet isolated in the 17 different plant species from which the corresponding dimers had been isolated; and 7 were known and had been isolated in the same plant sources of the corresponding dimers. A targeted analysis of several natural extracts from specific plant sources would allow the identification of known or new molecules with potential and/or specific biological activities and, in a final analysis, would confirm the relative biosynthetic mechanism.     

Routine failure in Macedonia: a critique of the Global Financial Crisis from the periphery

In most Western analyses, the Global Financial Crisis (GFC) constituted a systemic failure that spread across the entire capitalist system from the United States. That was not, however, the discourse that circulated in (and about) Macedonia – a peripheral country that had been mired in economic disasters since its transition from socialism. Local experts and citizens believed that Macedonia had not been severely impacted by the GFC. This essay asks how economic crises and their aftermaths are experienced and evaluated when they are effectively routine or ‘normal’. Overall, it argues that, in a landscape punctuated by continual disruption, the GFC appeared not as a failure, but as a new reconfiguration of power that strengthened the position of new elites through increasingly oppressive relations of (inter)dependence.     

Dopamine D3 receptor antagonists: The quest for a potentially selective PET ligand. Part one: Lead identification

The synthesis and SAR of a new series of potent and selective dopamine D₃ receptor antagonists is reported.